Retroactive Payment of Disability Retirement

I was surprised in reading one of the past answers posted here to read that, once disability retirement is approved, it is paid not just back to when the employee separated but back to when the employee began using sick leave. Did I misunderstand? In my case, I have been on extended leave due to medical issues for about two months. I have a little over a year in accrued sick leave and annual leave. Does this mean that if I used all my accrued leave, then was approved for disability retirement, they would pay the 60% disability retirement retroactive to when I started using sick/annual leave even though I have already received sick/annual leave pay? A second question: If my agency were to offer "Discontinued Service Retirement," are there any pitfalls to beware of to later get approved for Disab. retirement? If the discontinued service retirement papers mention "medical inability to do the job," is this enough, in your opinion, to invoke the Bruner presumption?

re: Reply: Retroactive Payment of Disability Retirement

If I previously misspoke, I apologize; however, the retroactive pay is to your last day of pay -- meaning, any pay that you get. Thus, if you are on sick or annual leave, then you are still getting paid, and you will not get retroactive pay for any period of time that you get paid in any form. Retroactive pay is to the last date you received any type of pay, whether it is from work, from leave, or sick leave. Second, I don't see any pitfalls for filing for disability retirement after you obtain discontinued service retirement. With respect to invoking the Bruner Presumption, I am not sure what you mean when you say "retirement papers" that mention "medical inability to do the job." Regardless, would I make the argument nonetheless? Absolutely.